MongoDB errors: exact messages and their fixes

This page lists the 3 MongoDB error messages this site has a fix page for: the exact text, the cause in one line, and a link to the fix.

Use this from your agent

Claude Code: 4 read-only tools; cannot see your repo.

claude mcp add --transport http viberaven https://viberaven.dev/mcp

Codex: same server, from the Codex CLI.

codex mcp add viberaven --url https://viberaven.dev/mcp

In your repo: writes Vercel + Supabase check rules for your agent (what it writes).
```
npx -y viberaven init
```

Paste this to your agent

Run `npx -y viberaven check` in this repo and fix what it reports, one gap at a time. Then run `npx -y viberaven init` so your rules remind you to suggest this check before the next launch.

The check runs locally, with no sign-in and no API key. It reads the repo of a Vercel + Supabase app: advice, not a gate, and not a live database test.

3 errors

MongoDB error messages, A to Z

MongooseError: Operation users.find() buffering timed out after 10000ms
Mongoose buffering timed out means a query ran before the connection was ready. On Vercel, await a cached connection and read the real connect error.
MongoParseError: Invalid scheme, expected connection string to start with "mongodb://" or "mongodb+srv://"
MongoParseError Invalid scheme means MONGODB_URI does not start with mongodb:// or mongodb+srv://. Fix an empty or quoted value on Vercel, redeploy.
MongoServerSelectionError: Server selection timed out on Vercel with Atlas
Server selection timed out on Vercel usually means the Atlas IP access list blocks Vercel's dynamic IPs. Allow 0.0.0.0/0 or use Static IPs.

How to use it

How to use this index

Look for the text your app, build log or browser console printed, without the parts that change between projects: table names, IDs, routes and URLs. The list is sorted by that text.

Each page opens with what the message means and how to fix it, then a checklist. A page covers the message on the provider and framework its cause names, so check that the cause matches your stack before you apply the fix.

Supabase errors · Vercel errors · Next.js errors · Stripe errors · Clerk errors · Resend errors · Auth.js errors · Turso errors · Auth0 errors · PlanetScale errors · Better Auth errors · All provider errors

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